If you want a premade raft, there are a couple options. I like the NRS packages. Have a bit wider stance and nice take down frames. Nice thing I will say about raft frames, they're VERY simple. But, you will be spending some money to buy new. I don't like the Aire Rafts, they make awesome catarafts, but their Puma series are great whitewatering boats, but don't like the tracking of them in a fishing sense. Too narrow for my tastes. One bad thing about a raft, you can't widen them if you want. Best thing to do is piece one together. I LOVE Maravia rafts. Have run a few, and handle great. Didn't use them for fishing, but you can get a feel how the boat tracks when running them. Plus, you can custom order with Flames and color options. So, basically, you can by an NRS frame and put it on a Maravia raft. There is Fishcraft out there that has them, but looks like they are running Star tubes and rafts, and I don't care for them. Didn't like construction and feel of material (like a lesser grade for a "whitewater" quality boat). NRS for the money, is a great deal though. I've never had a chance to run their boats, but another to check out is Sotar. They make about the best cataraft and rafts in the world. Their name says it all. I love their catarafts. Top of the line if you demand the best. But cost is there as well too. But if they make half as good of raft as they do cataraft, you'll be more then pleased with them. I know most of my friends who are still whitewater guides outfit their companies with Sotar rafts and catarafts. Nice thing, the tubes are designed for stability in whitewater and fishing.
I have an Aire Super Puma with custom frame which very handily fishes two people and a rower. I tend to use it when the water is too low for my drift boat. it is narrow, but I have been very pleased with it. For trout fishing for example on the Yakima, I think it's rowing characteristics allow you to hold the boat better to focus on a pod of fish, then say a Moravia or other wider raft would.
Moravia's are wonderful rafts though and SOTAR are the mercedes of WW rafts. You probably ought to row each of them to make up your mind. I personally like the way the Super Puma rows.
E-mail me if you want to know more. If you are nearby, perhaps you can try my raft out.
Hope you will have a fishing experience like the one in Luke Chapter 5:6-11 !